Vertical Hall Device Comprising a Slot in the Hall Effect Region

ABSTRACT

A vertical Hall device includes a Hall effect region, a separator, a first plurality of contacts, and a second plurality of contacts. The Hall effect region includes a first straight section, a second straight section that is offset parallel to the first straight section, and a connecting section that connects the first straight section and the second straight section. The separator separates a portion of the first straight section from a portion of the second straight section. The first and second plurality of contacts are arranged in or at the surface of the first and second straight sections, respectively. With respect to a first clock phase of a spinning current scheme, the first plurality of contacts comprises a first supply contact and a first sense contact. The second plurality of contacts comprises a second supply contact and a second sense contact.

TECHNICAL FIELD

Embodiments of the present invention relate to a vertical Hall deviceand to a sensing method. Further embodiments of the present inventionrelate to a patterned tub for vertical Hall devices.

BACKGROUND

Vertical Hall sensors typically comprise a Hall effect region that isformed within a substrate, such as a semiconductor substrate. VerticalHall sensors respond to magnetic field components parallel to thesubstrate or, more precisely, parallel to a main surface of thesubstrate.

Typically, vertical Hall sensors have one problem in common, namely anoffset error. The offset is the output signal in the absence of themagnetic field (component) which the sensor should detect. The origin ofthe offset error is basically a slight asymmetry of the device. Thisasymmetry can be caused by asymmetry in the geometrical shape (which ofcourse one tries to avoid). Yet, even in the case of perfect or nearperfect geometrical asymmetry, the electrical potential distribution inthe device causes an asymmetry, due to the junction field-effect. Thejunction field-effect is caused by the fact that a Hall sensor typicallycomprises a Hall effect region that is formed as a tub of oppositedoping type than the surrounding substrate. Accordingly, the activeregion (i.e., the Hall effect region) of the Hall sensor is limited by asmall pn-junction which causes the Hall sensor to exhibit a field effecttransistor-like behavior. The junction field-effect causesnonlinearities and limits the maximal achievable value of magneticsensitivity.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a vertical Hall device thatcomprises a Hall effect region, a separator, a first plurality ofcontacts and a second plurality of contacts. The Hall effect regioncomprises a first straight section, a second straight section that isoffset parallely to the first straight section, and a connecting sectionthat connects the first straight section and the second straightsection. The separator is configured to separate a portion of the firststraight section from a portion of the second straight section. Thefirst plurality of contacts is arranged in or at a surface of the firststraight section. In an analog manner, the second plurality of contactsis arranged in or at a surface of the second straight section. Withrespect to a first clock phase of a spinning current scheme, the firstplurality of contacts comprises a first supply contact and a first sensecontact. Still with respect to the first clock phase of the spinningcurrent scheme, the second plurality of contacts comprises a secondsupply contact and a second sense contact.

Further embodiments of the present invention provide a vertical Halldevice that comprises a Hall effect region formed in a semiconductorsubstrate and an electrically insulating slot formed within a portion ofthe Hall effect region. The electrically insulating slot is formed froma surface of the semiconductor substrate. The vertical Hall devicefurther comprises a first plurality of contacts arranged in or at thesurface of a first section of the Hall effect region. The firstplurality of contacts is distanced from corners of the Hall effectregion. The vertical Hall device also comprises a second plurality ofcontacts that is arranged in or at the surface of a second section ofthe Hall effect region. The second plurality of contacts is distancedfrom corners of the Hall effect region and at an opposite side of theelectrically insulating slot than the first plurality of contacts. Withrespect to a first clock phase of a spinning current scheme, the firstplurality of contacts comprises a first supply contact and a first sensecontact and the second plurality of contacts comprises a second supplycontact and a second sense contact.

Further embodiments of the present invention provide a sensing methodfor sensing a magnetic field parallel to a surface of a substrate. Thesensing method comprises applying an electrical supply to a Hall effectregion formed within the substrate. The Hall effect region comprises afirst straight section, a second straight section that is offsetparallely to the first straight section, and a connecting section thatconnects the first straight section and the second straight section. Afirst plurality of contacts is arranged in or at the surface of thefirst straight section. The first plurality of contacts is distancedfrom a first end and a second end of the first straight section. Asecond plurality of contacts is arranged in or at a surface of thesecond straight section. The second plurality of contacts is distancedfrom a first end and a second end of the second straight section.Applying the electrical supply occurs via a first supply contact amongthe first plurality of contacts and a second supply contact among thesecond plurality of contacts. The sensing method further comprisessensing a sense signal between a first sense contact among the firstplurality of contacts and a second sense contact among the secondplurality of contacts. The sensing method also comprises transitioningfrom a first clock phase of a spinning current scheme to a second clockphase by applying the electrical supply or another electrical supply tothe first sense contact and the second sense contact. The sensing methodfurther comprises sensing a further sense signal between the firstsupply contact and the second supply contact and determining an outputsignal indicative of the magnetic field on the basis of the sense signaland the further sense signal.

Further embodiments of the present invention provide a sensing methodfor sensing a magnetic field parallel to a surface of a substrate, thesensing method comprising applying an electrical supply to a Hall effectregion formed within the substrate. An electrically insulating slot isformed within a portion of the Hall effect region from the surface ofthe semiconductor substrate. A first plurality and a second plurality ofcontacts is arranged in or at the surface of a first section and asecond section of the Hall effect region. The first plurality and thesecond plurality of contacts are distanced from corners of the Halleffect region. Applying the electrical supply occurs via a first supplycontact among the first plurality of contacts and a second supplycontact among the second plurality of contacts. The sensing methodfurther comprises sensing a sense signal between a first sense contactamong the first plurality of contacts and a second sense contact amongthe second plurality of contacts. The sensing method also comprisestransitioning from a first clock phase of a spinning current scheme to asecond clock phase by applying the electrical supply or anotherelectrical supply to the first sense contact and the second sensecontact. The sensing method further comprises sensing a further sensesignal between the first supply contact and the second supply contactand determining an output signal indicative of the magnetic field on thebasis of the sense signal and the further sense signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are described herein makingreference to the appended drawings.

FIG. 1A shows a schematic plan view of a vertical Hall device accordingto a first embodiment;

FIG. 1B shows a schematic cross-section of the vertical Hall deviceshown in FIG. 1A along line B-B;

FIG. 1C shows a schematic cross-section of the vertical Hall deviceshown in FIG. 1A along line C-C;

FIG. 1D shows a schematic perspective cross-section of the vertical Halldevice shown in FIGS. 1A to 1C;

FIG. 1E shows a similar cross-section as FIG. 1C through a vertical Halldevice according to a second embodiment that is similar to the firstembodiment;

FIG. 1F shows a similar cross-section as FIG. 1C through a vertical Halldevice according to a further embodiment that is similar to the firstembodiment;

FIG. 1G shows a schematic, perspective view of the Hall effect regionand the buried n-doped layer (nBL) of the embodiment shown in FIG. 1F;

FIG. 2A shows a schematic plan view of a vertical Hall device accordingto a third embodiment;

FIG. 2B shows a schematic plan view of a vertical Hall device accordingto a variation of the third embodiment;

FIG. 3 shows a schematic plan view of a vertical Hall device accordingto a fourth embodiment;

FIG. 4 shows a schematic plan view of a vertical Hall device accordingto a fifth embodiment;

FIG. 5 shows a schematic plan view of a vertical Hall device accordingto a sixth embodiment;

FIG. 6 shows a schematic plan view of a vertical Hall device accordingto a seventh embodiment;

FIG. 7 shows a schematic plan view of a vertical Hall device accordingto an eight embodiment;

FIG. 8 shows a schematic plan view of a vertical Hall device accordingto a ninth embodiment;

FIG. 9 shows a schematic plan view of a vertical Hall device accordingto a tenth embodiment;

FIG. 10 shows a schematic plan view of a vertical Hall device accordingto an eleventh embodiment;

FIG. 11 shows a schematic plan view of a vertical Hall device accordingto a twelfth embodiment;

FIG. 12 shows a schematic plan view of a vertical Hall device accordingto a thirteenth embodiment;

FIG. 13 shows a schematic flow diagram of a sensing method according toan embodiment; and

FIG. 14 shows a schematic flow diagram of a sensing method according toanother embodiment.

Equal or equivalent elements or elements with equal or equivalentfunctionalities are denoted in the following description by equal orsimilar referenced signs.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following description, a plurality of details are set forth toprovide a more thorough explanation of embodiments of the teachingsdisclosed herein. However, it will be apparent to one skilled in the artthat embodiments disclosed herein may be practised without thesespecific details. Features of the different embodiments describedhereinafter may be combined with each other, unless specifically notedotherwise.

A Hall effect region may be a tub or well of a first conductivity typewhich is embedded within a substrate or a tub/well of oppositeconductivity type. This structure may cause an electrical isolation ofthe Hall effect region against the substrate in particular if theresulting pn-junction is reverse biased.

When the vertical Hall device comprises two or more Hall effect regionsor when a Hall effect region comprises two or more sections, these maybe (at least partially) isolated from each other. The electricalisolation of two Hall effect regions or sections against each other maytake several forms. According to a first form of isolation, the two ormore Hall effect regions/sections may be isolated in lateral directionby means of one or more trenches. Typically, the trenches are not empty,but filled with an electrically conducting, p-doped polycrystallinesilicon which contacts the underlying p-substrate. For galvanicinsulation of the Hall effect region(s) against the p-poly Si-plugs ofthe trenches the trench walls are lined with a thin oxide. As anotheroption, the Hall effect region may be isolated towards the bottom bymeans of an SOI (silicon-on-insulator) structure. Although the Halleffect region typically has a single conductivity type, it may beadvantageous to configure the doping concentration in an inhomogeneousmanner, i.e., spatially variable. In this manner, a high concentrationof the doping agent may occur in the area of the contact, as is usualwith deep CMOS contacts. In the alternative, a layering of differentlystrongly doped layers may be sought after, as is the case with, e.g., aburied layer. Such a layering may result, to some extent, fromtechnological reasons relative to other electronic structures that areformed within the substrate. The device of the vertical Hall device thenmay need to be reconciled with these circumstances, even though thelayering may, in fact, be unfavourable for the vertical Hall device.

Another form of isolation may be achieved by measures that reduce orsubstantially prevent an electric current from flowing in one or moresub-regions of a Hall effect region. For example, the electric currentmay be offered an alternative current path that has lower ohmicresistance, (possibly by several orders of magnitude) than asubstantially parallel current path would have that goes through theHall effect region. The current path having the lower ohmic resistancemay be a conductor formed in or on the surface of the tub.

Preferably, the Hall effect region may be an n-doped semiconductor asthis provides a three times higher mobility and consequently a higherHall factor than with a p-doped semiconductor. The doping concentrationin the functional part of the Hall effect region is typically in therange of 10¹⁵ cm⁻³ to 10¹⁷ cm⁻³.

Embodiments of the vertical Hall device typically make use of thespinning current principle, in which supply- and sense-terminals areexchanged in consecutive clock phases/operating phases. A sense terminalin a vertical Hall device responds to an electric current passingunderneath it. A magnetic field (parallel to the die surface andperpendicular to the current streamlines) can efficiently lift up orpull down the potential at the contact (which typically is at thesurface of the die). The term “vertical Hall effect” or “vertical Halldevice” may be thought of as being derived from the fact that the Halleffect in a vertical Hall device acts in a vertical direction (if thesurface of the substrate is assumed to be horizontal). Contacts at theend of a tub (or semiconductor Hall effect region) typically are not, oronly negligibly, subject to current streamlines passing underneath them.

FIG. 1A shows a schematic plan view of a vertical Hall device accordingto a first embodiment. The vertical Hall device comprises a Hall effectregion 11 which is subdivided in a first straight section 111, a secondstraight section 112, and a connecting section 115. The approximatelocations of (imaginary) boundaries between the first straight section111 and the connecting section 115, as well as between the connectingsection 115 and the second straight section 112 are indicated in FIG. 1Aby dotted lines. The first and second straight sections 111, 112 areelongate and parallel to each other. The second straight section 112 isoffset parallel from the first straight section 111 in a direction thatis orthogonal to a longitudinal direction of the first and secondstraight sections 111, 112. The connecting section 115 connects thefirst straight section 111 and the second straight section 112 of theHall effect region 11. In particular, the connecting section 115connects a central portion of the first straight section 111 with acentral portion of the second straight section 112.

The vertical Hall device further comprises two separators 51, 52 in theform of trenches that are formed in the substrate. As an alternative tothe separators 51, 52 being in the form of trenches, the separationcould be achieved by means of p-doped tubs. The first separator 51separates a left portion of the first straight section 111 from a leftportion of the second straight section 112. The second separator 52separates a right portion of the first straight section 111 from a rightportion of the second straight section 112. Note that designations“left” and “right” refer to the representation of the vertical Halldevice in FIG. 1A, only, and shall not be construed as a possiblerestriction or limitation. In particular, the separator 51 shall preventa direct current flow from a contact 21 to a contact 34. The separator52 shall prevent a current flow from a contact 23 to a contact 31.Hence, the separation prevents that the significant current portionsflow in direction parallel to the magnetic field (B-field)—theseparation forces a direction on the current flow that is perpendicularto the B-field, since only then a strong Hall signal is generated.

The separators 51, 52 may also be understood as slots that are formedwithin a portion of the Hall effect region 11 from the surface of thesemiconductor substrate. Departing from the embodiment illustrated inFIG. 1A, other embodiments may have a single separator, only, such as asingle trench or a single slot. The trench(es) may be unfilled, lined,or (partly) filled with an electrically insulating material, such assilicon oxide. In case the trench or slot is lined with an electricallyinsulating material, the interior of the trench or slot may be filledwith a doped material, such as a p-doped material, e.g., poly-Si and thesurface of the rectangle may be coated by some thin insulating material(oxide).

The vertical Hall device schematically illustrated in FIG. 1A furthercomprises a first plurality of contacts 20 arranged in or at the surfaceof the first straight section 111. The first plurality of contacts 20 isdistanced from a first end 81 and a second end 82 of the first straightsection 111. Furthermore, the first plurality of contacts 20 is alsodistanced from corners 71, 72, 73, and 74 of the Hall effect region 11.In a similar manner, a second plurality of contacts 30 is arranged in orat a surface of the second straight section 112. The second plurality ofcontacts 30 is distanced from a first end 83 and a second end 84 of thesecond straight section 112 and also from the corners 71 to 74 of theHall effect region 11. Optionally, the contact 21 and other outmostcontacts could reach all the way to the end 71—a distance is notnecessary in such alternative embodiments. For some embodiments the term“distanced from an end/corner” may be defined as a minimal distancebetween the plurality of contacts and the nearest end 81 to 84 of thecorresponding straight section 111, 112 and/or the nearest corner 71-74of the Hall effect region 11 is greater than an average spacing of thecontacts within the plurality of contacts. Note that, until furthernotice, the corners should be interpreted in a broad manner and may be,for example, rounded corners or other structures that form a transitionfrom one section of the Hall effect region 11 to another section.

The first plurality of contacts 20 comprises three contacts 21, 22, and23. The second plurality of contacts 30 comprises three contacts 31, 32,and 34. The contacts are typically regions of high conductivity that arearranged in or at a surface of the Hall effect region 11. The contacts21, 22, 23, 31, 32, and 34 are connected to different terminals C1, C2,C3, C1′, and C3′ as follows: contact 21 to terminal C1, contacts 22 and32 to terminal C2, contact 23 to terminal C3, contact 31 to terminalC1′, and contact 34 to terminal C3′.

During a first clock phase of a spinning current scheme, the contactsmay be connected in the following manner. Contacts 21, 31, 22, and 32function as supply contacts so that an electrical current is supplied tothe Hall effect region 11 via the contacts 21 and 31. At the contacts 22and 32 the electrical current is extracted from the Hall effect region11. Note that the contacts 22 and 32 are electrically connected by aconnection 42. In alternative embodiments, the contacts 21 and 31 couldbe electrically connected to each other, as well. The contacts 23 and 34function as sense contacts. In the first straight section 111 of theHall effect region 11 the electrical current flows along arc-shapedcurrent stream lines from the contact 21 to the contact 22 that extendinto the drawing plane of the graphical representation of FIG. 1A.Within the second straight section 112 of the Hall effect region 11 theelectrical current follows arc-shaped current streamlines betweencontacts 31 and 32 and extending into the drawing plane in therepresentation of FIG. 1A, too. A magnetic field in the directionindicated by the arrow B in FIG. 1A influences the current distributionwithin the first and second straight sections 111, 112, which in turnleads to a measurable difference of the electrical potentials at thesense contacts 23 and 34.

The embodiment illustrated in FIG. 1A shows one option of how the Halleffect region 11 may be patterned as an “I”-Hall effect region. The twoslots 51, 52 isolate C1 from C3′ and C3 from C1′. Note that despitethese isolations provided by the slots 51, 52, the first and secondstraight sections 111, 112 are still part of the same Hall effect region11: The single Hall effect region 11 is patterned by the slots 51 and52.

FIG. 1B shows a schematic cross-section of the vertical Hall device fromFIG. 1A along the line BB-BB. The Hall effect region 11, of which onlythe connecting section 115 is visible in cross-section in FIG. 1B, isformed within a semiconductor substrate 10. The semiconductor substrate10 has a main surface 8 from which the separators 51, 52 (slots ortrenches or tubs of opposite polarity type (p-type or n-type)) extendinto the substrate 10. The substrate 10 is, for example, a p-dopedsemiconductor substrate, whereas the Hall effect region 11 is n-doped.The Hall effect region 11 extends to a lower interface or boundary 9.The separators 51, 52 extend further into the substrate than the lowerinterface 9, so that the corresponding portions of the first straightsection 111 and the second straight section 112 are separated by theseparators 51, 52 and also the pn-junction between the n-doped Halleffect region 11 and the p-doped semiconductor substrate 10. In case theseparators 51, 52 are implemented as p-doped insulation tubs, thep-doped insulation tubs do not reach beneath the pn-junction between theHall effect region 11 and the substrate 10, but (exactly) to this depth.

FIG. 1C shows a schematic cross-section through the vertical Hall deviceof FIG. 1A along the line CC-CC. Here it can be seen that the separator51 effectively insulates the corresponding portions of the firststraight section 111 and the second straight section 112. Nevertheless,first and second straight sections 111, 112 are both part of the sameHall effect region 11, because they are connected to each other by theconnecting section 115.

FIG. 1D shows a schematic perspective cross-section of the vertical Halldevice shown in FIGS. 1A-1C. The cross-section plane is substantiallyparallel to the cross-section plane shown in FIG. 1C, however, slightlyoffset so that the cross-section goes through contacts 21 and 34. It canbe seen that the separator or trench 51 extends through the Hall effectregion 11 and also beyond the lower interface 9 into the semiconductorsubstrate 10. The separators 51, 52 are illustrated as empty slots inFIG. 1D for the sake of illustration. Typically however, the separators51, 52 are filled.

FIG. 1E shows a schematic cross section which is similar to theschematic cross-section of FIG. 1C, however, for a slightly differentembodiment of the vertical Hall device. According to this embodiment,the separator 51 does not extend all the way down to the interface 9which forms the lower boundary of the Hall effect region 11. A deep Halleffect region portion 118 beneath the separator 51 (and also theseparator 52) connects the first straight section 111 and the secondstraight section 112. While in the embodiment according to FIGS. 1A-1C,the separators 51, 52 are deeper than the Hall effect region 11 to makea “perfect” slot, it is also possible to use a “slot” that is shallowerthan the Hall effect region 11, as in the embodiment according to FIG.1E. This latter type of “slot” is not a “perfect” slot, becauseelectrical current can pass underneath it from the first straightsection 111 to the second straight section 112. However, it still hassome insulating function between the first straight section 111 and thesecond straight section 112 (particularly if the “slot” 51 is notnarrow, but wide). In some technologies there might be no deep p-tubavailable to make a perfect slot and then one may resort to a shallow“slot” approximation.

The Hall effect region 11 may extend to a first depth into thesemiconductor substrate 10. The separator(s) 51, 52 may extend to asecond depth into the semiconductor substrate that is smaller than thefirst depth. In this case, the first straight section 111 and the secondstraight section 112 are also connected, in addition to the connectingsection(s) 115, 116, via a deep Hall effect region portion that islocated beneath the separator(s) 51, 52 (i.e., further into thesubstrate relative to the main surface 8).

FIG. 1F shows a schematic cross section through a vertical Hall deviceaccording to a further embodiment. The cross section in FIG. 1F issimilar to the cross section of FIG. 1C. The difference is that thevertical Hall device illustrated in FIG. 1F comprises a buried layer 119beneath the Hall effect region 11. The buried layer 119 may be a socalled n-buried layer. According to the embodiment of FIG. 1F, theburied layer 119 is structured in substantially the same manner as theHall effect region 11. The separators 51, 52 pass through the Halleffect region 11 and also through the buried layer 119. The buried layer119 also comprises a section beneath the connecting section 115 of theHall effect region 11. An interface 19 separates the buried layer 119from the substrate 10.

FIG. 1G shows a schematic, perspective view of the Hall effect region 11and the buried layer 119 of the Hall effect device according to FIG. 1F.It can be seen that the buried layer 119 is structured or shaped in thesame manner as the Hall effect region 11. According to the embodimentschematically shown in FIGS. 1F and 1G, it is optionally possible that aburied layer 119 that is completely congruent to the Hall effect region11 is present beneath the Hall effect region 11. The buried layer mayhave the following effect. Due to the identical structure of the buriedlayer 119 and of the Hall effect region, the buried layer 119 enforces ahomogeneous potential at the lower surface of the Hall effect region 11.In comparison, two distinct Hall effect regions that are connected onlyat the upper surface by means of wires or the like, the two distinctburied layers located beneath the two distinct Hall effect regions wouldbe at different potentials. As a result, the embodiment according toFIGS. 1F and 1G has a significantly different behavior (e.g., withrespect to the offset error) than an electrical connection of twodistinct Hall devices by means of their surface contacts, only.

Note that in the embodiment shown in FIGS. 1A to 1D and also in theslightly modified embodiments shown in FIG. 1E to 1G, the separators 51and 52 are depicted as empty, unfilled trenches, as this facilitates amore comprehensible graphical representation of the vertical Hall deviceaccording to embodiments. However, as an alternative, the separators 51,52 could be trenches that are lined with an electrically insulatingmaterial, such as an oxide. As another alternative, the separators 51,52 could be trenches that are filled with an electrically insulatingmaterial, e.g., oxide or the oppositely doped material of the Halleffect region 11 (that is, p-doped semiconductor within the trenchesforming the separators 51, 52, in case the Hall effect region 11 is ann-doped semiconductor). Yet another alternative for the separators 51,52 would be to line the trenches with an electrically insulatingmaterial and to fill the resulting cavity within the trenches with, forexample polycrystalline silicon (poly-Si) or another suitable materialthat can be deposited to fill the resulting cavity. Yet another optionfor the separators 51, 52 would be p-doped tubs formed within the Halleffect region 11.

In FIGS. 1A-1G the Hall effect region 11 has the shape of the letter “I”(or the letter “H” when looking from the side). In embodiments that willbe described next, the Hall effect region 11 is patterned in the form ofthe letter “O”. The “I”-Hall effect region can be thought of beingobtained by inverting the “O” Hall effect region, or vice versa.

FIG. 2A shows a schematic plan view of a vertical Hall device accordingto another embodiment in which the Hall effect region 11 is patterned inthe form of an “O”. The Hall effect region 11 comprises a first straightsection 111, a second straight section 112, a connecting section 115,and a further connecting section 116. The separator 51 is located in themiddle of the Hall effect region 11 and may be an unfilled trench, afilled trench, a lined trench, or a lined-and-filled trench.Accordingly, the vertical Hall device has the Hall effect region 11 thatconsists of a single tub, where the slot 51 is cut out. The slot 51 cutsout an inner part of the Hall effect region 11, so that the topology ofthe Hall effect region 11 is a ring structure when viewed from above.When considering the actual three-dimensional shape of the Hall effectregion 11, the same is a kind of (rectangular) torus. In contrast toother vertical Hall devices of the Hall effect region 11 is not astraight parallelepiped anymore, but a connected domain in 3D.

The slot or separator 51 divides the entire Hall effect region 11 intofour parts: an upper branch or section 111 (from contact 21/terminal C1over contact 23/terminal C2 to contact 22/terminal C3), a lower branch112 (from contact 32/terminal C3 over contact 34/terminal C4 to contact31/terminal C1), a left short or connecting section 115 (shorting theleftmost upper and lower contacts 28, 38), and a right short orconnecting section 116 (shorting the rightmost upper and lower contacts29, 39).

Five contacts 28, 21, 23, 22, and 29 are lined up on a line parallel tothe slot and above (with respect to the representation of FIG. 2A) theslot 51. Another five contacts 38, 32, 34, 31, and 39 are lined up on aline parallel to the slot 51 and below the slot 51. All leftmostcontacts 28, 38 and rightmost contacts 29, 39 are connected to a singlenetwork node 49. The three inner contacts 21, 23, 22, 32, 34, and 31 ofthe upper and lower branches 111, 112 constitute, or are connected to,the terminals C1 to C4 of the device, whereby the left contact 21 of theupper branch or straight section 111 is shorted to the right contact 31of the lower branch or straight section 112 in a diagonal fashion bymeans of a connection 41. In a similar manner the right contact 22 ofthe upper branch (straight section) 111 is shorted to the left contact32 of the lower branch (straight section) 112 (also in a diagonalfashion by means of a connection 42). This gives four terminals C1, C2,C3, and C4. In a first clock-phase of a spinning current scheme the oddterminals C1 and C3 act as supply terminals and the even contacts C2, C4as sense terminals. In a second clock phase of the spinning currentscheme the even contacts C2, C4 act as supply terminals and the oddcontacts C1, C3 as sense terminals.

The imaginary boundaries 81 to 84 between the four different sections111, 112, 115, 116 of the Hall effect region 11 are indicated by dottedlines in FIG. 2A. These boundaries 81 to 84 also define first and secondends of the first straight section 111 and the second straight section112. In FIG. 2A the boundaries 81 to 84 are illustrated as being theextensions of the edges of the separator 51, but this is not necessarilyso. Indeed, the straight sections 111 and 112 may extend beyond theedges of the separator 51. For example, the straight sections 111, 112may extend all the way to the left edge and the right edge of the Halleffect region 11 so that also the contacts 28, 29, 38, and 39 arearranged at the surface of the straight sections 111, 112. It can beseen that the first plurality of contacts 20 is distant from the firstend 81 and the second end 82 of the first straight section 111. In theembodiment schematically illustrated in FIG. 2A the distance between thefirst end 81 and the left contact 21 is greater than half of the spacingbetween the contacts of the first plurality of contacts 20. Inalternative embodiments the distance between the first end 81 and thenearest contact of the first plurality of contacts 20 (here contact 21)may be arbitrarily chosen, for example greater than 10%, 20%, 25%, 30%,or 40% of the spacing of contacts within the first plurality of contacts20. The same applies to the other ends 82, 83, and 84 and thecorresponding closest contacts of the first and second pluralities ofcontacts 20, 30.

The separator 51 has the task of conducting the current flow during thefirst clock phase from contact 21 to contact 22, thus having the currentpassing underneath contact 23, while preventing that significantportions of the current branch off towards contact 32 (which alwaysoccurs to a certain degree). During the second clock phase the separator51 has a similar task. The separator(s) is/are perpendicular to thedirection of the magnetic field component that is to be measured and areconfigured to guide a major portion of the current perpendicularly tothe magnetic field so that a strong Hall signal can be generated.

The first plurality of contacts 20 is also a certain minimal distanceaway from the corners 71 to 74 of the Hall effect region 11. Thecontacts 21, 23, and 22 are lined up on a line that is parallel and/orcoincides with a longitudinal axis of the first straight section 111.Similar observations can be made for the second plurality of contacts30, which is distanced from the first end 83 and the second end 84 ofthe second straight section 112. Furthermore, the second plurality ofcontacts 30 is also distanced from the corners 71-74 of the Hall effectregion 11.

The slot or separator 51 can be made as a trench as is common in BiCMOStechnologies: with these technologies, the interior of the slot 51 wouldtypically be chosen to be a p-doped material (e.g., poly-Si) and thesurface (interface to the Hall effect region 11) may typically be chosento be coated by some thin insulating material (e.g., oxide).Alternatively, the slot 51 can be made as a tub or well of inversedoping with respect to the Hall effect region 11: typically, the Halleffect region is n-doped, so that the slot 51 may be p-doped. Then, theslot 51 is contacted and a voltage is applied which is lower or equal tothe lowest potential in the Hall effect region 11 in order to make ajunction isolation between p-doped and n-doped regions. The p-dopedregion 51 may be deeper or just as deep as the Hall effect region 11 tomake a perfect slot. However, it is also possible to use a “slot” thatis shallower than the Hall effect region 11. This latter type of “slot”is not a perfect slot because current can pass underneath it from C2 toC4. However, it still has some isolating function between the upper andlower branches 111, 112 (particularly if the “slot 51 is not narrow, butwide”). In some technologies there might be no deep p-tub available tomake a perfect slot and then one may resort to a shallow “slot”approximation. In case a buried layer is present, the separator(s)should typically be sufficiently deep so as to reach the buried layer.In this manner the separator(s) may separate a first portion of theburied layer that is beneath the first straight section 111 from asecond portion of the buried layer that is beneath the second straightsection 112. Otherwise a significant amount of electrical current couldflow through the buried layer underneath the separator(s), thusdiminishing the effect of the separator(s).

FIG. 2B shows a schematic plan view of a vertical Hall device accordingto a variation of the embodiment shown in FIG. 2A. In the embodimentaccording to FIG. 2A, it would be desirable if approximately half of thecurrent would flow from contact 21 to contact 22 and would generate aHall signal at contact 23. It would further be desirable thatapproximately the other half of the current would flow from contact 31to contact 32 and would generate a Hall signal at contact 34. Inreality, a portion of the current flows from contact 21 to contact 32via contact 28, which is connected to contact 38 without generating aHall signal at any of the sense contacts 23, 34. The same also happensbetween contacts 31 and 22, where a portion of the current flows via theconnected contacts 39 and 29, without producing a Hall signal.

In order to reduce these current losses, the contacts 28 and 39 areconnected to a network node 49 a, while the contacts 29 and 38 areconnected to another network node 49 b. Hence, the single network node49 from FIG. 2A is replaced by two individual network nodes 49 a, 49 b.By varying the width of the separator 51 the remaining current lossescan be influenced: the wider the separator 51 (and the more narrow theconnecting sections 115, 116), the lower the current losses. Thismodification may be applied to all configurations having diagonalconnections between the upper and lower plurality of contacts, inparticular to the embodiments shown in FIGS. 3, 7 and 8 which will bedescribed below.

FIG. 3 shows a schematic plan view of a vertical Hall device accordingto a further embodiment in which the outer contacts are modifiedcompared to the embodiment shown in FIG. 2A. The vertical Hall deviceshown in FIG. 3 comprises outer contacts 328 and 329 that are as long asto reach from the upper branch 111 right through to the lower branch112. Again, the outer contacts or short circuit contacts 328, 329 areconnected to the single network node 49.

In the vertical Hall devices according to the embodiments shown in FIG.1A to FIG. 3 and also in most of the other embodiments, the firstplurality of contacts 20 and the second plurality of contacts 30 arepairwise aligned to each other along a direction defined by a paralleloffset of the first straight section 111 and the second straight section112. The parallel offset between the first and second straight sections111, 112 is typically orthogonal to the longitudinal axis of thestraight sections 111, 112. The property of pairwise alignment betweenthe first and second plurality of contacts 20, 30 means that one contactof the first plurality of contacts 20 may be translated in the directionand by the distance defined by the parallel offset between the first andsecond straight sections 111, 112 and then substantially coincides withits aligned contact of the second plurality of contacts 30. In otherwords, the positions of the contact within the first plurality ofcontacts 20 and the contact within the second plurality of contacts 30are mirror symmetric with respect to a mirror plane that passes throughthe separator 51 or the separators 51, 52. Typically, this mirror planeis parallel to the longitudinal axis of the first and second straightsections 111, 112 and orthogonal to the surface 8 of the semiconductorsubstrate 10.

According to some embodiments, at least one supply contact 21, 22 of thefirst plurality of contacts 20 is aligned with a supply contact 32, 31of the second plurality of contacts 30. At least one sense contact 23 ofthe first plurality of contacts 20 is aligned with a sense contact 34 ofthe second plurality of contacts 30. The embodiments shown in FIGS. 2and 3 are examples for this sort of alignment. In particular, not onlythe positions of the individual contacts within the first and secondplurality of contacts 20, 30 are pairwise aligned of each other, butalso with respect to whether the aligned contacts act as supply contactsor as sense contacts during the different clock phases of the spinningcurrent scheme. Note, however, that two aligned supply contacts might beconnected to different electrical supply potentials, as is the case in,e.g., the embodiments according to FIGS. 2 and 3. For example, thesupply contact 21 of the first plurality of contacts 20 may be connectedto a higher electrical potential than its pairwise aligned counterpart,contact 32, which may be connected to a lower electrical supplypotential during the first clock phase of the spinning current scheme. Asimilar observation can be made for two aligned sense contacts, e.g.,contacts 23 and 34 of the embodiments according to FIGS. 2 and 3 duringthe first clock phase of the spinning current scheme.

According to other embodiments, such as illustrated in FIGS. 1A to 1E,at least one supply contact 21 of the first plurality of contacts 20 maybe aligned with a sense contact 34 of the second plurality of contacts30, and at least one sense contact 23 of the first plurality of contacts20 may be aligned with a supply contact 31 of the second plurality ofcontacts 30.

As shown in FIGS. 2 and 3, the vertical Hall device may comprise afurther connecting section 116 that connects the first straight section111 and the second straight section 112 at a different position than theconnecting section 115. In this manner the first straight section 111,the second straight section 112, the connecting section 115, and thefurther connecting section 116 form a frame for the separator 51 (e.g.,slot or trench). The Hall effect region 11 forms a frame for theseparator 51 in that, at least in a lateral direction (i.e., parallel tothe substrate surface 8) the separator 51 is surrounded by the Halleffect region 11. In other words, the Hall effect region 11 “frames” theseparator or slot 51.

The vertical Hall device may further comprise a plurality of shortcircuit contacts 28, 29, 38, 39, 328, 329 arranged in or at the surfacesof the connecting section 115 and the further connecting section 116.The short circuit contacts may be electrically connected to a singlenetwork node 49.

The first plurality of contacts 20 may comprise at least three contacts21, 22, 23. The second plurality of contacts 30 may comprise at leastthree contacts 31, 32, 34. Referring to the embodiments of FIGS. 2 and 3and in a representative and by no means limiting manner, for the sake ofexplanation, at least one contact 21, 22 of the first plurality ofcontacts 20 may be electrically connected to at least one of

in the case of contact 21: a next but one contact 21 of an alignedcontact 32 of the second plurality of contacts 30, and

in the case of contact 22: a preceding but one contact 32 of an alignedcontact 31 of the second plurality of contacts 30.

The aligned contact 32, 31 is aligned to the at least one contact 21, 22of the first plurality of contacts 30. As will be described with respectto embodiments according to FIGS. 7 and 8, this pattern may be extended.

Instead of regarding the short circuit contacts as being separate fromthe first plurality of contacts 20 and/or the second plurality ofcontacts 30, the first plurality of contacts 20 may comprise a firstshort circuit contact as an outmost contact. The second plurality ofcontacts 30 may comprise a second short circuit contact as an outmostcontact. The first and second short circuit contacts may be electricallyconnected to a single network node 49.

The vertical Hall device according to embodiments may further comprisefour terminals, two of which may be configured to function as supplyterminals and the other two being configured to function as senseterminals during the first clock phase of the spinning current scheme.Each of the four terminals C1 to C4 may be connected to exactly oneouter contact of the first plurality of contacts 20 or the secondplurality of contacts 30 and to at least one inner contact of the secondplurality of contacts 30 and the first plurality of contacts 20.

FIG. 4 shows a schematic plan view of a vertical Hall device accordingto embodiments. As can be seen in FIG. 4, it is also possible to dowithout the outmost contacts or short circuit contacts (referencenumerals 28, 29, 38, 39, 328, and 329 in FIGS. 2 and 3) by usingadditional slots or separators 53, 54 that shape or pattern the Halleffect region 11 by a multiple connected topology. The Hall effectregion 11 further comprises a third straight section 113 and a fourthstraight section 114 in addition to the first and second straightsections 111, 112, the connecting section 115, and the furtherconnecting section 116. The third straight section 113 and the thirdstraight section 114 are offset parallel to the first and secondstraight sections 111, 112. The connecting section 115 also connects thethird straight section 113 and the fourth straight section 114 with thefirst and second straight sections 111, 112. The further connectingsection 116 also connects the first, second, third, and fourth straightsections 111-114 with each other, however, at another location than theconnecting section 115. As a result, the Hall effect region 11 has aladder-like structure (multiple connected topology). According to theembodiment shown in FIG. 4, no contacts are arranged in or at thesurface of the third straight section 113 and the fourth straightsection 114.

A separator 53 in the form of a slot or a trench separates at least aportion of the first straight section 111 from a portion of the thirdstraight section 113. Another separator 54 in the form of a slot or atrench separates at least a portion of the second straight section 112from at least a portion of the fourth straight section 114. The verticalHall device thus comprises the second slot 53 and the third slot 54 inaddition to the first slot 51. The second and third slots 53, 54 areformed within further portions of the Hall effect region 11, so that theHall effect region 11 has a ladder-like structure.

In FIG. 4 it is of course also possible to use only two slots (e.g., toomit the lower slot 54)—but the presence of both slots 53, 54 increasethe symmetry of the device and this is believed to result in a better(smaller) residual offset or zero-point error.

Note that in FIG. 4 the Hall effect region 11 itself makes a shortbetween the upper branch (first straight section) 111 and the lowerbranch (second straight section) 112. If the Hall effect region 11 hastoo high impedances, one can shape its lateral dimensions (e.g., width)to approximate a good short. There are CMOS technologies where theepitaxial layer (nEpi) may be used as the Hall effect region 11.

Furthermore, there are CMOS technologies which use a highly conductiveburied layer (nBL, wherein the “n” stands for n-doped) underneath theepitaxial layer. This nBL acts as a good short supporting the lessconductive Hall effect region 11 (both are electrically connected inparallel): in FIG. 4, the nBL would have, for example, the same shape asthe Hall effect region 11, simply the nBL is below the Hall effectregion 11 and both are in good contact (there is no isolation betweenthem). One advantage of the nBL is that it pulls the charge carriersaway from the top surface of the Hall effect region 11, which typicallyhas lots of traps and defects, thereby reducing flicker noise andlifetime-drift of the vertical Hall device.

FIG. 5 shows a schematic plan view of a vertical Hall device accordingto an embodiment similar to the vertical Hall device shown in FIG. 4. Inparticular, it is possible to improve the short circuit of the first andsecond straight sections 111, 112 in the embodiments of FIG. 4 byadditional contacts 528 in the shape of a ring or frame (which may alsodegenerate to a “U” if, for example, the upper slot 53 and hence thethird straight section 113 are omitted).

FIG. 6 shows a schematic plan view of a vertical Hall device accordingto embodiments which may be regarded as a further development of theembodiments shown in FIG. 3. In the embodiment of FIG. 6 the two outercontacts 328, 329 are connected with a horizontal strip 327 of anelectrically conducting material, e.g., a metal. This strip 327 mayextend adjacent to the main surface 8 of the semiconductor substrate 10of the Hall effect region 11. It may in particular cover the separator51 which is indicated in FIG. 6 by a box drawn in dashed line, as it isbelow the strip 327. The strip 327 typically makes no contact to thetub(s) 11 or trench(es) 51 below. If the slot 51 needs a contact, a holetypically needs to be provided in the strip 327 to get access to theslot 51 below.

FIG. 7 shows a schematic plan view of a vertical Hall device accordingto a further embodiment. An even better degree of symmetry may beobtained by adding one contact in the upper and lower branches 111, 112,and thus to the first plurality of contacts 20 and a second plurality ofcontacts 30. The hatch patterns show that each of the terminals C1 to C4represents a short circuit of an inner contact and an outer contact sothat there is no preferences/asymmetry between the four terminals C1 toC4. In the first plurality of contacts 20 the leftmost contact 24 hasbeen added which is short-circuited via a connection 44 to the contact34 of the second plurality of contacts 30. In the second plurality ofcontacts the contact 33 has been added as the leftmost and accordinglyas one of the outer contacts. The contact 33 is electrically connectedvia a connection 43 to the contact 23 of the first plurality of contacts20.

In FIG. 7 it can be seen that at least one contact of the firstplurality of contacts 20 is electrically connected to at least one of:

-   -   a next but one contact of an aligned contact within the second        plurality of contacts 30, and    -   a preceding but one contact of an aligned contact of the second        plurality of contacts 30.

The aligned contact is the contact within the second plurality ofcontacts 30 that is aligned to the at least one contact of the firstplurality of contacts 20. For example, the contact 24 is (pairwise)aligned to the contact 33, and vice versa. The next but one contact ofcontact 33 is contact 34 within the second plurality of contacts 30. Itcan be seen that the contacts 24 and 34 are electrically connected viathe electrical connection 44. Another example is contact 22 which is(pairwise) aligned to contact 31 of the second plurality of contacts 30.The preceding but one contact of contact 31 is contact 32 within thesecond plurality of contacts 30. This contact 32 is electricallyconnected to the contact 22 of the first plurality of contacts 20, viathe electrical connection 42.

This scheme may be generalized as schematically illustrated in FIG. 8which shows a schematic plan view of a vertical Hall device according toa further embodiment. Again, the different hatch patterns indicate whichof the contacts are electrically connected to each other. In FIG. 8 itbecomes apparent that a particular contact within the first plurality ofcontacts 20 is connected to those contacts within the first plurality ofcontacts 20, which are four contacts or a multiple of four contacts awayfrom said contact, if the contacts of the first plurality of contacts 20are numbered, for example, from left to right in an ascending order. Asimilar observation can be made for the contacts of the second pluralityof contacts 30. Between the first and second plurality of contacts 20,30 there is, however, an offset of two contacts. This may be expressedas follows: Let m be the index of a particular contact within the firstplurality of contacts 20. Let n be an integer with m≧1. Then the contactm is connected to a contact m±4n within the first plurality of contactsunder the following boundary condition:

1≦m±4n≦M

with M being the number of contacts within the first plurality ofcontacts. The contact m is also connected to contacts within the secondplurality of contacts 30 having an index according to

1≦m+2±4n≦N ₂,

wherein N₂ is the number of contacts within the second plurality ofcontacts (typically M₁=N₂).

Example: Let M=N=12 as in the embodiment shown in FIG. 8. The contactwith the index m=7 (reference numeral 23-2) is connected to contacts #3(reference numeral 23-1) and #11 (reference numeral 23-3) within thefirst plurality of contacts 20. The contact with the index m=7 is alsoconnected to the contacts #1 (reference numeral 33-1), #5 (referencenumeral 33-2), and #9 (reference numeral 33-3) within the secondplurality of contacts 30.

FIGS. 9 and 10 show schematic plan views of vertical Hall devicesaccording to two further embodiments (“2×4C devices”). In contrast toother embodiments, there are no electrical connections between a contactin the upper row (first plurality of contacts) and its correspondingaligned contact in the lower row (second plurality of contacts), butonly diagonal connections between a contact in the upper row and thenext but one contact or the preceding but one contact in the lower row.The vertical Hall device according to FIG. 9 or 10 may be operated usinga four-phase spinning current scheme as follows:

positive negative positive negative supply supply sense sense contactcontact contact contact clock phase 1 C1 C3 C2 C4 clock phase 2 C2 C4 C3C1 clock phase 3 C3 C1 C4 C2 clock phase 4 C4 C2 C1 C3

FIG. 9 shows a first option for the separator 51 resulting in an“O”-shape of the Hall effect region 11. Note that during clock phase 1 aportion of the electric current would branch off from the upper contactC1 to the lower contact C3 via connection section 115, thus notproducing a Hall signal.

FIG. 10 shows a second option for the separator 51 resulting in an“I”-shape of the Hall effect region 11. With this configuration, currentflows from the upper row of contacts to the lower row of contacts aresubstantially inhibited.

FIG. 11 shows a schematic plan view of a vertical Hall device accordingto a further embodiment which can be obtained from the embodiment shownin FIG. 2A by deleting one contact from the upper and lower branches,i.e., from the first and second straight sections 111 and 112.Furthermore, the diagonal connections 41 and 42 between upper and lowerbranches in the embodiment of FIG. 2A are also deleted. Once again, itis emphasized that according to embodiments a single Hall effect region11 is patterned or subdivided into two or more straight sections 111,112 (if the technology that is used for manufacturing the vertical Halldevice provides a buried layer, then this buried layer is typically alsopatterned identically to the Hall effect region). In contrast, othervertical Hall devices comprise two or more distinct Hall effect regions(each having its own buried layer, if the technology provides a buriedlayer) which are only electrically connected via contacts at the uppersurface of the Hall effect regions in a ring circuit or in anotherelectrical arrangement.

During the first clock phase of the spinning current scheme anelectrical current is supplied to the Hall effect region 11 via thecontact 21 and extracted from the Hall effect region 11 via the contact32, for example. Depending on the prevalent magnetic field approximatelyone half of the electrical current flows to the left after havingentered the Hall effect region 11 at the contact 21, through theconnecting portion 115 and the left portion of the second straightsection 112 until it leaves the Hall effect region 11 at the contact 32.The remaining electrical current (again, approximately the half of theentire electrical current) first flows to the right within the firststraight section 111, then through the further connecting section 116and then to the left until it leaves the Hall effect region 11 atcontact 32, as well. From an electrical point of view the Hall effectregion 11 can be regarded as a parallel connection between contacts 21and 32 of two substantially identical resistances. The first resistancerepresents the portion of the Hall effect region 11 relative to the“counter-clockwise” current flow between contacts 21 and 32 (i.e., viaconnecting section 115). The second resistance represents that portionof the Hall effect region 11 relative to the “clockwise” current flowdirection between contact 21 and 32 (i.e. via the further connectingsection 116).

Note that in FIG. 11 the boundaries between the first and secondstraight sections 111, 112 and the connecting section 115 and thefurther connecting section 116 are assumed to be different. However,this is only to demonstrate that the short circuit contacts 28, 29, 38,39 may be regarded as being arranged in or at the surface of thefirst/second straight sections 111, 112, respectively. Furthermore, itis pointed out that there is no electrical connection between the leftshort circuit contacts 28, 38 and the right short circuit contacts 29,39. Nevertheless, such an electrical production could be provided inalternative embodiments.

During the first clock phase, sense signals may be obtained at contacts23 and 34. During a second clock phase of the spinning current scheme,the contacts 23 and 34 act as supply contacts. In exchange, the contacts21 and 32 act as sense contacts.

FIG. 12 shows a schematic plan view of a vertical Hall device accordingto further embodiments. In comparison to other embodiments (e.g. theembodiment according to FIG. 11) the embodiment according to FIG. 12 maybe obtained by making the slot 51 wider in order to have a squareaperture. No short circuit contacts 28, 29, 38, 39 are present in theembodiment according to FIG. 12 (although it would be possible to placethen in the four corners of the ring structure). Instead, two furthercontacts 1026 and 1027 are added at the left of this ring structure, inparticular in or at the surface of the connecting section 115. Two othercontacts 1036 and 1038 are also added at the right of this ringstructure, in particular in or at the surface of the further connectingportion 116. The connecting section 115 and the further connectingsection 116 are substantially identical (except for a 90 degreerotation) to the first and second straight sections 111, 112. Inparticular, the connecting section 115 and the further connectingsection 116 are straight sections that have the same length as the firststraight section 111 and the second straight section 112. They areoriented orthogonally to the first straight section 111 and the secondstraight section 112 so that the Hall effect region 11 has a squareshape with the separator 51 being rectangular (in the embodimentaccording to FIG. 12 it is even square, as well) and located between thefirst straight section 111, the second straight section 112, theconnecting section 115, and the further connecting section 116. Thecontacts 1026 and 1027 form a third plurality of contacts which isarranged in or at the surface of the connecting section 115. The thirdplurality of contacts is distanced from a first end 81 and a second end83 of the connecting section 115. The contacts 1036 and 1038 form afourth plurality of contacts arranged in or at a surface of the furtherconnecting section 116, distanced from a first end 82 and a second end84 of the further connecting section 116.

In other words, the vertical Hall device of the embodiment according toFIG. 12 can be described as having a Hall effect region of square shapeand the slot 51 being located at a center of the Hall effect region 11.The first, second, third, and fourth pluralities of contacts have arotational symmetry with respect to contact locations and contactfunctions as supply contacts and sense contacts during the first clockphase of the spinning current scheme. Typically, this rotationalsymmetry is also maintained during a second clock phase and potentialfurther clock phases of the spinning current scheme, yet with differentcontact functions for the individual contacts. As mentioned above, therotational symmetry of the contact functions typically relates towhether the contacts in question function as supply contacts or sensecontacts, in general, but not to the exact electrical connection (e.g.,“positive supply contact” vs. “negative supply contact”) of thesecontacts.

With the vertical Hall device shown in FIG. 12 it is possible to measuremagnetic fields parallel to the y-direction by means of terminals C1,C2, C5, and C6. Magnetic fields in the x-direction may be measured bymeans of terminals C3, C4, C7, and C8.

The vertical Hall device according to FIG. 12 may be operated in thefollowing way: in a first clock cycle positive supply is connected toterminals C1 and C5. Negative supply is connected to terminals C3 andC7. The terminals C2 and C6 function as sense terminals indicative ofthe y-component of the magnetic field B_(y), whereas the terminals C4and C8 function as sense terminals for the x-component of the magneticfield B_(x).

In a second clock cycle the supply and sense terminals are swapped.

The x-component of the magnetic field B_(x) is computed byadding/subtracting the signals C4-C8 of the first clock cycle andsignals C3-C7 of the second clock cycle.

The y-component of the magnetic field B_(y) is computed byadding/subtracting signals C2-C6 of the first clock cycle and signalsC1-C5 of the second clock cycle.

The region inside the aperture can be used for circuitry or, e.g., aconventional Hall plate (that detects magnetic field components verticalto the die surface (substrate surface)).

The vertical Hall device illustrated in FIG. 12 is very symmetric. Notethat in the embodiment according to FIG. 12 the contacts are in the fourbranches or straight sections of the Hall effect region 11, whereasother vertical Hall effect devices with a square, ring-shaped Halleffect region may have the contacts in the corners 71 to 74 of thedevice. The embodiment according to FIG. 12 also makes apparent that,for example, the first plurality of contacts may have as few as twocontacts, namely the contact 1021 (a supply contacted during the firstclock phase) and the contact 1023 (a sense contact during the firstclock phase). Due to the 90° rotational symmetry of the device, this isalso true for the second, third, and fourth pluralities of contacts. Inother words, the i-th plurality of contacts may comprise at least twocontacts. Or, the i-th plurality of contacts may comprise at least asupply contact for the first clock phase and a sense contact for thefirst clock phase.

Yet another way to pattern the Hall effect region 11 is obtained byinverting the “O”-Hall effect region 11 of FIGS. 2 to 9 to an “I”-Halleffect region, as, for example, illustrated in FIGS. 1A-1G.

FIG. 13 shows a schematic flow diagram of a sensing method according toembodiments. The method comprises a step 1102 of applying an electricalsupply to a Hall effect region that is formed within a substrate,typically a semiconductor substrate. The Hall effect region comprises afirst straight section, a second straight section that is offsetparallel to the first straight section, and a connecting section thatconnects the first straight section and the second straight section. Insome embodiments the Hall effect region may also comprise a furtherconnecting section, leading to a ring-shaped Hall effect region. A firstplurality of contacts is arranged in or at the surface of the firststraight section. This first plurality of contacts is distanced from afirst end and also from a second end of a first straight section. Asecond plurality of contacts is arranged in or at a surface of thesecond straight section, distanced from a first end and a second end ofthe second straight section. Applying the electrical supply occurs via afirst supply contact among the first plurality of contacts and a secondsupply contact among the second plurality of contacts. Typically, anelectrical supply current is fed to the Hall effect region via the firstsupply contact and extracted from the Hall effect region at the secondsupply contact, or vice versa. The sensing method is typically intendedto be performed in connection with a vertical Hall device that is suitedfor the so-called spinning current scheme. Accordingly, the step 1102and also the subsequent step 1104 which will be described next relate toa first clock phase of the spinning current scheme.

During the step 1104 a sense signal is sensed between a first sensecontact among the first plurality of contacts and a second sense contactamong the second plurality of contacts. In particular in the presence ofa magnetic field component parallel to the substrate surface andperpendicular to a net current flow direction between the first supplycontact and the second supply contact, the first sense contact and thesecond sense contact will typically be at different electricalpotentials, (mainly) due to the Hall effect. This difference ofelectrical potential can be measured or sensed, thus providing the sensesignal. Other options for obtaining the sense signal are also possible,such as measuring an electrical current or a difference of electricalcurrents that flow through the first and second sense contacts.

During a step 1106 a transition from the first clock phase of thespinning current scheme to a second clock phase is performed by applyingthe electrical supply to the first sense contact and the second sensecontact. As an alternative, the supply to the first and second supplycontacts which were used as supply contacts during the first clockphase, may be interrupted, and another supply for the first and secondsense contacts (during the first clock phase) is activated for thesecond clock phase. In other words, the functions of the supply contactsand the sense contacts are interchanged by transitioning from the firstclock phase to the second clock phase.

Step 1108 is the sensing step during the second clock phase so that afurther sense signal is sensed between the first (former) supply contactand the second (former) supply contact.

Finally, an output signal that is indicative of the magnetic field onthe basis of the sense signal and the further sense signal is determinedat a step 1109.

This sensing method may basically be performed with any of the verticalHall devices shown in and described in connection with FIGS. 1A to 12.Accordingly, specific details of the vertical Hall devices describedabove may also be used for further defining the sensing method asoutlined in the flow diagram of FIG. 13. The same remark is also truefor the schematic flow diagram of FIG. 14 which also relates to asensing method, however according to different embodiments.

In the schematic flow diagram of FIG. 14, an electrical supply issupplied to a Hall effect region during a step 1202. The Hall effectregion is formed within a substrate, typically a semiconductorsubstrate. A slot is formed within a portion of the Hall effect region,typically from the surface of the substrate. In alternative embodimentsthe slot may also be formed within the semiconductor substrate by meansof appropriate manufacturing techniques. A first plurality and a secondplurality of contacts are arranged in or at the surface of a firstsection and a second section of the Hall effect region, respectively.The first plurality and the second plurality of contacts are distancedfrom corners of the Hall effect region. Applying the electrical supplyoccurs via a first supply contact among the first plurality of contactand a second supply contact among the second plurality of contacts.

At a step 1204 a sense signal is sensed between a first sense contactamong the first plurality of contacts and a second sense contact amongthe second plurality of contacts.

A transition from a first clock phase of a spinning current scheme to asecond clock phase is performed at step 1206. Accordingly, theelectrical supply is applied to the first sense contact and the secondsense contact. Alternative options as discussed above in connection withstep 1106 may also be used here.

At a step 1208 a further sense signal is sensed between the first supplycontact and the second supply contact. Then an output signal indicativeof the magnetic field is determined on the basis of the sense signal andthe further sense signal.

Although some aspects have been described in the context of anapparatus, it is clear that these aspects also represent a descriptionof the corresponding method, where a block or device corresponds to amethod step or a feature of a method step. Analogously, aspectsdescribed in the context of a method step also represent a descriptionof a corresponding block or item or feature of a correspondingapparatus. Some or all of the method steps may be executed by (or using)a hardware apparatus, like for example, a microprocessor, a programmablecomputer or an electronic circuit. In some embodiments, some one or moreof the most important method steps may be executed by such an apparatus.

In the foregoing Detailed Description, it can be seen that variousfeatures are grouped together in embodiments for the purpose ofstreamlining the disclosure. This method of disclosure is not to beinterpreted as reflecting an intention that the claimed embodimentsrequire more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive subject matter may lie inless than all features of a single disclosed embodiment. Thus thefollowing claims are hereby incorporated into the Detailed Description,where each claim may stand on its own as a separate embodiment. Whileeach claim may stand on its own as a separate embodiment, it is to benoted that—although a dependent claim may refer in the claims to aspecific combination with one or more other claims—other embodiments mayalso include a combination of the dependent claim with the subjectmatter of each other dependent claim or a combination of each featurewith other dependent or independent claims. Such combinations areproposed herein unless it is stated that a specific combination is notintended. Furthermore, it is intended to include also features of aclaim to any other independent claim even if this claim is not directlymade dependent to the independent claim.

It is further to be noted that methods disclosed in the specification orin the claims may be implemented by a device having means for performingeach of the respective steps of these methods.

Furthermore, in some embodiments a single step may include or may bebroken into multiple sub steps. Such sub steps may be included and partof the disclosure of this single step unless explicitly excluded.

The above described embodiments are merely illustrative for theprinciples of the present invention. It is understood that modificationsand variations of the arrangements and the details described herein willbe apparent to others skilled in the art. It is the intent, therefore,to be limited only by the scope of the impending patent claims and notby the specific details presented by way of description and explanationof the embodiments herein.

What is claimed is:
 1. A vertical Hall device, comprising: a Hall effectregion that comprises a first straight section, a second straightsection that is offset from and parallel to the first straight section,and a connecting section that connects the first straight section andthe second straight section; a separator that separates a portion of thefirst straight section from a portion of the second straight section; afirst plurality of contacts arranged in or at a surface of the firststraight section; a second plurality of contacts arranged in or at asurface of the second straight section; wherein, with respect to a firstclock phase of a spinning current scheme, the first plurality ofcontacts comprises a first supply contact and a first sense contact, andthe second plurality of contacts comprises a second supply contact and asecond sense contact.
 2. The vertical Hall device according to claim 1,wherein the first plurality of contacts is distanced from a first endand a second end of the first straight section, and wherein the secondplurality of contacts is distanced from a first end and a second end ofthe second straight section.
 3. The vertical Hall device according toclaim 1, wherein the first plurality of contacts and the secondplurality of contacts are pair-wise aligned to each other along adirection defined by a parallel offset of the first straight section andthe second straight section.
 4. The vertical Hall device according toclaim 3, wherein at least one supply contact of the first plurality ofcontacts is aligned with a supply contact of the second plurality ofcontacts, and at least one sense contact of the first plurality ofcontacts is aligned with a sense contact of the second plurality ofcontacts.
 5. The vertical Hall device according to claim 3, wherein atleast one supply contact of the first plurality of contacts is alignedwith a sense contact of the second plurality of contacts, and at leastone sense contact of the first plurality of contacts is aligned with asupply contact of the second plurality of contacts.
 6. The vertical Halldevice according to claim 1, further comprising a further connectingsection that connects the first straight section and the second straightsection so that the first straight section, the second straight section,the connecting section and the further connecting section form a framefor the separator.
 7. The vertical Hall device according to claim 6,further comprising a third plurality of contacts arranged in or at thesurface of the connecting section, distanced from a first end and asecond end of the connecting section; and a fourth plurality of contactsarranged in or at a surface of the further connecting section, distancedfrom a first end and a second end of the further connecting section. 8.The vertical Hall device according to claim 7, wherein the connectingsection and the further connecting section are straight sections, thathave the same length as the first straight section and the secondstraight section and are oriented orthogonally to the first straightsection and the second straight section so that the Hall effect regionhas a square shape with the separator being rectangular and locatedbetween the first straight section, the second straight section, theconnecting section, and the further connecting section; and wherein thefirst, second, third, and fourth plurality of contacts have a rotationalsymmetry with respect to contact locations and contact functions assupply contacts and sense contacts during the first clock phase of thespinning current scheme.
 9. The vertical Hall device according to claim6, further comprising a plurality of short circuit contacts arranged inor at the surfaces of the connecting section and the further connectingsection, wherein the short circuit contacts are electrically connectedto a single network node.
 10. The vertical Hall device according toclaim 9, wherein the vertical Hall device is disposed in a semiconductorsubstrate, the vertical Hall device further comprising a strip ofelectrically conducting material extending at a surface of thesemiconductor substrate along the separator and electrically connectingthe short circuit contacts.
 11. The vertical Hall device according toclaim 1, further comprising a further separator that separates a furtherportion of the first straight section from a further portion of thesecond straight section, wherein the connecting section is between theseparator and the further separator.
 12. The vertical Hall deviceaccording to claim 1, wherein the first plurality of contacts comprisesat least three contacts and the second plurality of contacts comprisesat least three contacts; and wherein at least one contact of the firstplurality of contacts is electrically connected to at least one of: anext but one contact and a preceding but one contact of an alignedcontact of the second plurality of contacts, the aligned contact beingaligned to the at least one contact of the first plurality of contacts.13. The vertical Hall device according to claim 1, wherein the firstplurality of contacts comprises a first short circuit contact as anoutmost contact, and wherein the second plurality of contacts comprisesa second short circuit contact as an outmost contact, and wherein thefirst and second short circuit contacts are electrically connected to asingle network node.
 14. The vertical Hall device according to claim 1,wherein the Hall effect region comprises a third straight section thatis parallely offset to the first straight section and the secondstraight section; wherein the vertical Hall device further comprises asecond separator that separates a portion of the third straight sectionfrom a portion of the second straight section; and wherein theconnecting section also connects the third straight section with thefirst straight section and the second straight section.
 15. The verticalHall device according to claim 14, further comprising a third pluralityof contacts arranged in or at the surface of the third straight section,distanced from a first end and a second end of the third straightsection.
 16. The vertical Hall device according to claim 1, wherein thevertical Hall device is disposed in a semiconductor substrate andwherein the Hall effect region extends to a first depth into thesemiconductor substrate and wherein the separator extends to a seconddepth into the semiconductor substrate that is smaller than the firstdepth so that the first straight section and the second straight sectionare also connected via a deep Hall effect region portion beneath theseparator.
 17. The vertical Hall device according to claim 1, furthercomprising four terminals, two of the terminals being configured tofunction as supply terminals and the other two of the terminals beingconfigured to function as sense terminals during the first clock phaseof the spinning current scheme, wherein each of the four terminals isconnected to exactly one outer contact of the first plurality ofcontacts or the second plurality of contacts and to at least one innercontact of the second plurality of contacts and the first plurality ofcontacts.
 18. The vertical Hall device according to claim 1, furthercomprising a third straight section and a fourth straight section thatare offset from and parallel to the first straight section and thesecond straight section; and a further connecting section that connectsthe first straight section, the second straight section, the thirdstraight section, and the fourth straight section; wherein theconnecting section also connects the third straight section and thefourth straight section with the first straight section and the secondstraight section so that the Hall effect region has a ladder-likestructure.
 19. The vertical Hall device according to claim 18, whereinthe first straight section and the second straight section are innersections of the ladder-like structure and the third straight section andthe fourth straight section are outer sections; the vertical Hall devicefurther comprising a short circuit ring structure extending along thethird straight section, the connecting section, the fourth straightsection, and the further connecting section, thus framing the firststraight section, the second straight section, the first plurality ofcontacts, and the second plurality of contacts.
 20. The vertical Halldevice according to claim 1, further comprising an electricallyconducting buried layer arranged at a lower surface of the Hall effectregion that is congruent to the Hall effect region.
 21. A vertical Halldevice comprising: a Hall effect region formed in a semiconductorsubstrate; an electrically insulating slot formed within a portion ofthe Hall effect region from a surface of the semiconductor substrate; afirst plurality of contacts arranged in or at the surface of a firstsection of the Hall effect region, the first plurality of contacts beingdistanced from corners of the Hall effect region; and a second pluralityof contacts arranged in or at the surface of a second section of theHall effect region, the second plurality of contacts being distancedfrom corners of the Hall effect region and at an opposite side of theelectrically insulating slot than the first plurality of contacts;wherein, with respect to a first clock phase of a spinning currentscheme, the first plurality of contacts comprises a first supply contactand a first sense contact, and the second plurality of contactscomprises a second supply contact and a second sense contact.
 22. Thevertical Hall device according to claim 21, wherein the first pluralityof contacts and the second plurality of contacts are pair-wise alignedto each other across the electrically insulating slot.
 23. The verticalHall device according to claim 21, wherein the Hall effect region framesthe electrically insulating slot.
 24. The vertical Hall device accordingto claim 21, further comprising a third plurality of contacts arrangedin or at the surface of a connecting section, distanced from a first endand a second end of the connecting section; and a fourth plurality ofcontacts arranged in or at a surface of a further connecting section,distanced from a first end and a second end of the further connectingsection.
 25. The vertical Hall device according to claim 21, wherein theHall effect region has a square shape and the electrically insulatingslot is located at a center of the Hall effect region and wherein thevertical Hall device further comprises: a third plurality of contactsarranged in or at the surface of a third section of the Hall effectregion, distanced from a first end and a second end of the thirdsection; and a fourth plurality of contacts arranged in or at a surfaceof a fourth section of the Hall effect region, distanced from a firstend and a second end of the fourth section; wherein the first, second,third, and fourth plurality of contacts have a rotational symmetry withrespect to contact locations and contact functions as supply contactsand sense contacts during the first clock phase of the spinning currentscheme.
 26. The vertical Hall device according to claim 21, wherein thefirst plurality of contacts comprises at least three contacts and thesecond plurality of contacts comprises at least three contacts; andwherein at least one contact of the first plurality of contacts iselectrically connected to at least one of a next but one contact and apreceding but one contact of an aligned contact of the second pluralityof contacts, the aligned contact being aligned to the at least onecontact of the first plurality of contacts.
 27. The vertical Hall deviceaccording to claim 21, wherein the Hall effect region extends to a firstdepth into the semiconductor substrate and wherein the electricallyinsulating slot extends to a second depth into the semiconductorsubstrate that is smaller than the first depth so that a first sectionand a second section at opposite sides of the electrically insulatingslot are also connected via a deep Hall effect region portion beneaththe electrically insulating slot.
 28. The vertical Hall device accordingto claim 21, further comprising a second electrically insulating slotand a third electrically insulating slot formed within further portionsof the Hall effect region so that the Hall effect region has aladder-like structure.
 29. A sensing method for sensing a magnetic fieldparallel to a surface of a substrate, the method comprising: applying anelectrical supply to a Hall effect region formed within the substrate,the Hall effect region comprising a first straight section, a secondstraight section that is offset from and parallel to the first straightsection, and a connecting section that connects the first straightsection and the second straight section, a first plurality of contactsbeing arranged in or at the surface of the first straight section,distanced from a first end and a second end of the first straightsection, a second plurality of contacts being arranged in or at asurface of the second straight section, distanced from a first end and asecond end of the second straight section wherein applying theelectrical supply occurs via a first supply contact among the firstplurality of contacts and a second supply contact among the secondplurality of contacts; sensing a sense signal between a first sensecontact among the first plurality of contacts and a second sense contactamong the second plurality of contacts; transitioning from a first clockphase of a spinning current scheme to a second clock phase by applyingthe electrical supply to the first sense contact and the second sensecontact; sensing a further sense signal between the first supply contactand the second supply contact; and determining an output signalindicative of the magnetic field on the basis of the sense signal andthe further sense signal.
 30. A sensing method for sensing a magneticfield parallel to a surface of a semiconductor substrate, the methodcomprising: applying an electrical supply to a Hall effect region formedwithin the substrate, wherein an electrically insulating slot is formedwithin a portion of the Hall effect region from the surface of thesemiconductor substrate and a first plurality and a second plurality ofcontacts arranged in or at the surface of a first section and a secondsection of the Hall effect region, the first plurality and the secondplurality of contacts being distanced from corners of the Hall effectregion, wherein applying the electrical supply occurs via a first supplycontact among the first plurality of contacts and a second supplycontact among the second plurality of contacts; sensing a sense signalbetween a first sense contact among the first plurality of contacts anda second sense contact among the second plurality of contacts;transitioning from a first clock phase of a spinning current scheme to asecond clock phase by applying the electrical supply to the first sensecontact and the second sense contact; sensing a further sense signalbetween the first supply contact and the second supply contact; anddetermining an output signal indicative of the magnetic field on thebasis of the sense signal and the further sense signal.